Lumpsum calculator · one-time investment
Lumpsum Calculator 2026: One-Time Mutual Fund Investment Growth
By Pratik Bajoria, Chartered Accountant & NISM-certified Research Analyst · Updated 3 October 2026 · tax rules for FY 2026-27
A lumpsum investment puts a single amount to work at once — a bonus, maturity proceeds or an inheritance. This lumpsum calculator compounds it at an assumed annual return and shows the inflation-adjusted value. Example: ₹5,00,000 at an assumed 11% for 10 years ≈ ₹14,19,710. Returns used on this page are illustrative assumptions, not forecasts for any fund.
Estimated future value after compounding
₹14.2 L
Lumpsum formula (compound interest)
FV = P × (1 + r)^n · Real value = FV ÷ (1 + inflation)^n
P = amount invested, r = assumed annual return, n = years. For CAGR in reverse — what return turned P into FV — use CAGR = (FV/P)^(1/n) − 1; for multiple cash flows use XIRR (XIRR vs CAGR explained).
Lumpsum return table at an assumed 12% a year
| Invested | 5 years | 10 years | 15 years | 20 years | 25 years |
|---|---|---|---|---|---|
| ₹1,00,000 | ₹1.76 lakh | ₹3.11 lakh | ₹5.47 lakh | ₹9.65 lakh | ₹17.00 lakh |
| ₹5,00,000 | ₹8.81 lakh | ₹15.53 lakh | ₹27.37 lakh | ₹48.23 lakh | ₹85.00 lakh |
| ₹10,00,000 | ₹17.62 lakh | ₹31.06 lakh | ₹54.74 lakh | ₹96.46 lakh | ₹1.70 crore |
| ₹25,00,000 | ₹44.06 lakh | ₹77.65 lakh | ₹1.37 crore | ₹2.41 crore | ₹4.25 crore |
How the return assumption changes ₹10 lakh over 15 years
| Assumed return | Future value | Gain | In today's ₹ (6% inflation) |
|---|---|---|---|
| 6% | ₹23.97 lakh | ₹13.97 lakh | ₹10.00 lakh |
| 8% | ₹31.72 lakh | ₹21.72 lakh | ₹13.24 lakh |
| 10% | ₹41.77 lakh | ₹31.77 lakh | ₹17.43 lakh |
| 12% | ₹54.74 lakh | ₹44.74 lakh | ₹22.84 lakh |
| 14% | ₹71.38 lakh | ₹61.38 lakh | ₹29.78 lakh |
A 6% return only keeps pace with 6% inflation — the real value stays at ₹10 lakh. The inflation figure is an assumption for illustration.
Rule of 72: years to double
| Return | Rule of 72 | Exact (compound) |
|---|---|---|
| 6% | 12.0 years | 11.9 years |
| 7.1% | 10.1 years | 10.1 years |
| 8% | 9.0 years | 9.0 years |
| 10% | 7.2 years | 7.3 years |
| 12% | 6.0 years | 6.1 years |
| 15% | 4.8 years | 5.0 years |
Chart: ₹5 lakh lumpsum at 8%, 10% and 12%
Tax on lumpsum mutual fund gains (FY 2026-27)
| Fund type | Held ≤ 12 months | Held > 12 months |
|---|---|---|
| Equity-oriented (≥65% domestic equity) | 20% (STCG) | 12.5% on LTCG above ₹1.25 lakh a year |
| Debt-oriented, bought on/after 1 Apr 2023 | Slab rate | Slab rate |
Illustration: ₹10,00,000 in an equity fund for 10 years at an assumed 12% → ₹31,05,848, a gain of ₹21,05,848. If this is your only equity gain that year, LTCG tax ≈ 12.5% × (gain − ₹1.25 lakh) + 4% cess = ₹2,57,510 (surcharge ignored). Spreading redemptions across years can use the ₹1.25 lakh exemption more than once — see LTCG tax harvesting. To estimate STCG/LTCG on an actual sale, use the equity capital gains calculator.
Source: SBI Mutual Fund Tax Reckoner FY 2026-27 (Income-tax Act, 2025; section 198 corresponds to the former section 112A).
Lumpsum, SIP or STP?
If you have the full amount today, a lumpsum invests it all immediately; a systematic transfer plan (STP) parks it in a liquid fund and moves a fixed amount into equity each month, trading some expected return for less timing risk. Compare outcomes in the SIP vs lumpsum calculator, plan monthly investing with the SIP calculator, and check what a regular plan's higher expense ratio costs with the direct vs regular calculator. Need a safe lumpsum with a fixed return? Try the FD calculator.
Investing a retirement lumpsum to draw a monthly income from it? That is the reverse of an STP: a systematic withdrawal plan pays you a fixed amount each month while the rest stays invested. The SWP calculator for monthly withdrawals shows how long a given amount lasts.
Investing a lumpsum toward a specific target? Work backwards from the amount and date with the goal calculator, or see how much SIP for ₹1 crore for SIP, step-up and lumpsum routes to ₹1 crore. Weighing an investment against prepaying a home loan? The EMI calculator shows prepayment savings.
Before you invest a lumpsum
Not sure whether to go in at once? Compare in the SIP vs lumpsum calculator. Redeeming an older fund to fund this one? Check the tax first in theequity capital gains calculator.
Selling a business stake? Get a rough equity value from thebusiness valuation calculator. Weighing solar instead of investing? The solar calculator shows payback.
Frequently asked questions
How is lumpsum mutual fund return calculated?
Future value = P × (1 + r)^n, where P is the amount invested, r the assumed annual return and n the years. ₹5,00,000 for 10 years at an assumed 11% grows to about ₹14,19,710. Real fund returns vary every year; the formula assumes a constant average.
What will ₹1 lakh become in 10 or 20 years?
At an assumed 12% a year, ₹1 lakh becomes about ₹3.11 lakh in 10 years and ₹9.65 lakh in 20 years. At 10% it is ₹2.59 lakh and ₹6.73 lakh. These are illustrations, not expected returns of any fund.
Is lumpsum better than SIP?
If markets rise steadily, money invested earlier compounds longer, so a lumpsum often ends higher than spreading the same amount over months. If markets fall soon after investing, a SIP or a systematic transfer plan (STP) from a liquid fund reduces regret. Neither is guaranteed to win; see the SIP vs lumpsum calculator.
How is a lumpsum mutual fund investment taxed in FY 2026-27?
For equity-oriented funds, gains on units held over 12 months are long-term and taxed at 12.5% above ₹1.25 lakh of total equity LTCG a year; gains within 12 months are taxed at 20%. Debt-oriented fund units bought on or after 1 April 2023 are taxed at your slab rate regardless of holding period. Add 4% cess (and surcharge if applicable).
What is the rule of 72?
Divide 72 by the annual return to estimate the years needed to double money: about 6 years at 12%, 7.2 years at 10% and 9 years at 8%. It is a quick approximation of the compound-interest formula.
Should I adjust for inflation?
Yes. At 6% inflation, ₹14,19,710 after 10 years buys what about ₹7,92,759 buys today. The calculator shows this 'value in today's ₹' so you can compare goals in current prices.
Educational tool only — not investment, tax or legal advice. Figures are formula-based illustrations using the stated assumptions; actual outcomes depend on notified rates, rules and your specific facts. Verify with official sources or a qualified professional before acting. Findost (findost.io) and PaisaGuru by Findost are not affiliated with Findoc, FinDost, or other similarly named brands. PaisaGuru is the AI wealth concierge of Findost.